Video monitoring system for a path

ABSTRACT

A number of monitoring devices are directed at a path. A controller is electrically coupled to the number of monitoring devices. The controller may be configured to cause video captured by each of the number of monitoring devices to be displayed and/or stored in response to determining that an image of a carrier that was previously present in an image field captured by a first monitoring device of the plurality of monitoring devices that is directed at a starting location of the path is absent from image field captured by the first monitoring device. Alternatively, the controller may be configured to determine whether the carrier travels between successive locations of the path within a certain length of time and to indicate a timing violation when the carrier fails to travel between the successive locations of the path within the certain length of time.

FIELD

The present disclosure relates generally to monitoring, and inparticular, the present disclosure relates to a monitoring system for apath, such as a path through a facility, e.g., a retail store or thelike.

BACKGROUND

Retail stores are common targets of theft. For example, small,high-priced items, such as small electronics, jewelry, etc., areparticularly susceptible to theft during stocking of these items. Tohelp combat theft of small, high-priced items, these items are oftenkept in their own stockroom that is locked, except during times when theitems are being removed for stocking. However, thefts can occur when theitems are being transported from the stockroom to their displaylocations. For example, an item may be hidden within the store,somewhere between the stockroom and the display location, for retrievalat a later time.

For the reasons stated above, and for other reasons stated below whichwill become apparent to those skilled in the art upon reading andunderstanding the present specification, there is a need in the art foralternative theft prevention and apprehension methods.

SUMMARY

One embodiment of the present invention provides a monitoring systemthat includes a plurality of monitoring devices directed at a path. Acontroller is electrically coupled to the plurality of monitoringdevices. The controller may be configured to cause video captured byeach of the plurality of monitoring devices to be displayed and/orstored in response to determining that an image of a carrier that waspreviously present in an image field captured by a first monitoringdevice of the plurality of monitoring devices that is directed at astarting location of the path is absent from image field captured by thefirst monitoring device. Alternatively, the controller may be configuredto determine whether the carrier travels between successive locations ofthe path within a certain length of time and to indicate a timingviolation when the carrier fails to travel between the successivelocations of the path within the certain length of time.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a portion of a facility, according to an embodimentof the invention.

FIG. 2 illustrates image fields captured by cameras along a path withinthe facility of FIG. 1, according to another embodiment of theinvention.

FIG. 3 is a flowchart of an embodiment of a method, according to anotherembodiment of the invention.

FIG. 4 is a flowchart of an embodiment of a method, according to anotherembodiment of the invention.

DETAILED DESCRIPTION

In the following detailed description, reference is made to theaccompanying drawings that form a part hereof, and in which is shown, byway of illustration, specific embodiments in which the invention may bepracticed. In the drawings, like numerals describe substantially similarcomponents throughout the several views. These embodiments are describedin sufficient detail to enable those skilled in the art to practice theinvention. It is to be understood that other embodiments may be utilizedand that process, electrical, and/or mechanical changes may be madewithout departing from the scope of the claimed subject matter. Thefollowing detailed description is, therefore, not to be taken in alimiting sense, and the scope of the present disclosure is defined onlyby the appended claims and equivalents thereof.

FIG. 1 illustrates a portion of a facility, such as a retail store 100,according to an embodiment. Retail store 100 may include a stockroom110, e.g., specifically for small, high-priced items, such as smallelectronics, jewelry, etc., and a sales floor 115. Sales floor 115includes a certain (e.g., predetermined) location 120, such as a displaylocation for displaying the small, high-priced items from stockroom 110.For one embodiment, stockroom 110 may include a certain location 122 atwhich a certain carrier (e.g., a conveyance) 125 may be loaded withitems for transporting the items from location 122 to location 120.Non-limiting examples of a carrier include a cart, e.g., a shoppingcart, a pallet on wheels, a forklift carrying a pallet, a box, basket,or pallet that is carried by one or more individuals, a wagon, a “handtruck,” a “hand truck” carrying a pallet, or any other vehicle capableof carrying items from one location to another.

For one embodiment, a certain (e.g., predetermined) path 135 extendsbetween location 122 of stockroom 110 and location 120 of sales floor115. For example, path 135 describes a specific route to be taken byemployees of retail store 100 when conveying items from location 122 instockroom 110 to location 120 of sales floor 115 at certain times ofday, e.g., when retail store 100 is closed, such as between 5:00 a.m.and 6:00 a.m., for stocking location 120 with these items. That is, path135 is specifically selected for conveying certain items, e.g., small,high-priced items, such as small electronics, jewelry, etc., fromlocation 122 in stockroom 110 to location 120, where location 122 is thestarting location and location 120 is the ending location of path 135.For one embodiment, the length of path 135 corresponds to the shortestdistance between locations 120 and 122. For another embodiment,stockroom 110 and sales floor 115 are in selective communication witheach other via a door 140 that selectively opens and closes a doorwaythrough which path 135 passes.

For one embodiment, carrier 125 is used specifically for conveying theitems from location 122 in stockroom 110 to location 120. Motion may beimparted to carrier 125 by an employee of the retail store who will bestocking location 120 with items from carrier 125. For otherembodiments, carrier 125 may be motorized. For example, carrier 125 maybe a forklift for carrying a pallet that contains the items for location120.

For one embodiment, monitoring devices, such as cameras 150 ₁ to 150_(N), e.g., analog or digital video cameras, are respectively directedat certain (e.g., predetermined) portions, e.g., path segments 155 ₁ to155 _(N), of path 135. For example, in one embodiment, cameras 150 ₁ to150 _(N) correspond to segments 155 ₁ to 155 _(N) on a one-to-one basis,where path segment 155 ₁ includes location 122 and path segment 155 _(N)includes location 120. During operation, cameras 150 ₁ to 150 _(N)respectively capture images, e.g., analog or digital images, of pathsegments 155 ₁ to 155 _(N). For another embodiment, cameras 150 ₁ to 150_(N) are specifically intended for taking video, e.g., analog or digitalvideo, of path segments 155 ₁ to 155 _(N) during certain (e.g.,predetermined) times of day, e.g., corresponding to the stocking timesfor location 120, such as when the retail store is closed. For oneembodiment, a portion of retail store 100 that includes path 135 andcameras 150 ₁ to 150 _(N) is a certain zone of the retail store, such asa security zone.

Cameras 150 are electrically coupled to a controller 160 to form amonitoring system, such as a video monitoring system, for monitoring themovement of carrier 125 along path 135. For one embodiment, the videomonitoring system is specifically dedicated to monitoring path 135. Foranother embodiment, the video monitoring system is a general videomonitoring system with cameras for monitoring the entire facility,including cameras 150 for monitoring path 135. Controller 160 andcameras 150 may be coupled to each other over a network, such as localarea network (LAN). For one embodiment, controller 160 may provide aninterface for a user to interact with cameras 150. For anotherembodiment, controller 160 may be a computer, such as personal computer,e.g., with a video display 162. Controller 160 may also include akeyboard (not shown) for inputting information into controller 160 and apointing device (not shown), such as a “mouse,” for controlling a cursordisplayed on video display 162.

For one embodiment, controller 160 includes a processor 164 forprocessing computer-readable instructions. These computer-readableinstructions are stored in a memory 165, such as a computer-usablemedia, and may be in the form of software, firmware, or hardware. Thecomputer-readable instructions configure controller 160 to cause thevideo monitoring system to perform the operations and methods describedbelow.

In a hardware solution, the computer-readable instructions are hardcoded as part of processor 164, e.g., an application-specific integratedcircuit (ASIC) chip. In a software or firmware solution, theinstructions are stored for retrieval by the processor 164. Someadditional examples of computer-usable media include static or dynamicrandom access memory (SRAM or DRAM), read-only memory (ROM),electrically-erasable programmable ROM (EEPROM or flash memory),magnetic media and optical media, whether permanent or removable. Mostconsumer-oriented computer applications are software solutions providedto the user on some form of removable computer-usable media, such as acompact disc read-only memory (CD-ROM) or digital video disc (DVD). Foranother embodiment, controller 160 may include a storage device 170,such as a hard drive, removable flash memory, etc., for storing imagedata corresponding to video images captured by cameras 150 ₁ to 150_(N).

For one embodiment, controller 160 may be electrically coupled to videomonitors 166 ₁ to 166 _(N), where video monitors 166 ₁ to 166 _(N) areconfigured to display video respectively received from cameras 150 ₁ to150 _(N). For example, controller 160 may be configured to respectivelydirect video from cameras 150 ₁ to 150 _(N) to video monitors 166 ₁ to166 _(N). For embodiments where controller 160 includes video display162, video from cameras 150 ₁ to 150 _(N) may be respectively displayedin “windows” displayed on video display 162.

For one embodiment, controller 160 may be configured to cause the videocaptured by each of cameras 150 ₁ to 150 _(N) to be displayed onrespective ones of video monitors 166 ₁ to 166 _(N) or on video display162 in response to carrier 125 leaving the segment of path 135 (e.g.,path segment 155 ₁) that includes location 122 in stockroom 110. Forexample, when controller 160 detects that an image of carrier 125 nolonger appears in the image of path segment 155 ₁, i.e., in the imagefield captured by camera 150 ₁ that contains the image of path segment155 ₁, controller 160 causes the video from each of cameras 150 ₁ to 150_(N) along path 135 to be displayed.

For one embodiment, controller 160 determines that the image of carrier125 no longer appears in the image field captured by camera 150 ₁ whenthe image of carrier 125 has been absent from that image field for acertain (e.g., predetermined) length of time, e.g., about five seconds.For another embodiment, controller 160 may be configured to cause imagedata corresponding to the images captured by each of cameras 150 ₁ to150 _(N) to be stored, e.g., as an image data file in a video imagedatabase, such as in storage device 170, in response to detecting thatthe image of carrier 125 no longer appears in the image field capturedby camera 150 ₁. For one embodiment, controller 160 is configured toactivate cameras 150 ₂ to 150 _(N) in response to controller 160determining that an image of carrier 125 no longer appears in the imagefield captured by camera 150 ₁ before displaying and/or storing imagedata from each of cameras 150 ₁ to 150 _(N). Displaying video and/orstoring image data from each of cameras 150 ₁ to 150 _(N) enablestracking of carrier 125 as carrier 125 traverses path 135.

For one embodiment, detecting that the image of carrier 125 no longerappears in the image field captured by camera 150 ₁ includes determiningthat a certain object (e.g., corresponding to carrier 125), e.g., of acertain (e.g., predetermined) size, that resided in the image fieldcaptured by camera 150 ₁ has been absent from that image field for acertain length of time, e.g., about five seconds. For one embodiment,controller 160 may be configured to determine the size, such as thearea, of an interior of a geometrical object, such as a box, formedaround the image of carrier 125 in the image field captured by camera150 ₁ by the user. The user may then store the size of the interior ofthe geometrical object as the certain size, e.g., in storage device 170.Then, each time an object has been absent from the image field capturedby camera 150 ₁, e.g., for the certain length of time, controller 160compares the size of that object to the certain size.

When the size of the object matches the certain size, controller 160determines that the image of carrier 125 has left the image fieldcaptured by camera 150 ₁ and thus carrier 125 has left path segment 155₁, and, consequently, controller 160 causes video from each of cameras150 ₁ to 150 _(N) to be displayed and/or stored. Otherwise, e.g., whenthe size of the object that left the image field captured by camera 150₁ is different from, e.g., larger or smaller than, the certain size,controller 160 will not cause the video from each of cameras 150 ₁ to150 _(N) to be displayed and/or stored, and for some embodiments,cameras 150 ₂ to 150 _(N) will not be activated. In this way, objectsentering and exiting the image field captured by camera 150 ₁, byentering and exiting path segment 155 ₁, whose sizes are different thanthat of carrier 125, meaning these objects are not carrier 125, will beignored. Note that in one embodiment, controller 160 uniquely identifiesan object whose image is captured by camera 150 ₁ as carrier 125 whenthe size of that object matches the certain size.

For one embodiment, controller 160, and thus the monitoring system, isconfigured to operate in a certain mode, such as a path-monitoring mode,e.g., a security-zone-monitoring mode, during certain times of day,e.g., corresponding to the stocking times for location 120. For example,controller 160 may be configured to detect that the image of carrier 125no longer appears in the image of path segment 155 ₁ only when themonitoring system is operating in the security-zone-monitoring mode,e.g., during the certain times of day.

For another embodiment, controller 160 may be configured to time theprogress of carrier 125 along path 135 only during the certain times ofday. That is, controller 160 may be configured to determine whethercarrier 125 travels between successive segments 155 within a certaintime. For example, controller 160 may determine whether carrier 125travels between successive locations 175, e.g., timing locations,respectively located within successive segments 155. That is, for oneembodiment, there is one location 175 within each segment 155.Alternatively, there may be one or more additional timing locations 175located in one or more of the segments 155, in which case the one ormore additional timing locations 175 are also included in the timing.

For one embodiment, controller 160 may be configured to determine thelength of time it takes for carrier 125 to travel between the locations175 within successive segments 155 and to compare that time to a certain(e.g., predetermined) length of time based on the distance between thecertain locations within the successive segments 155. For example, thelength of time it takes for carrier 125 to travel from a certainlocation 175 ₁, e.g., that coincides with starting location 122 instockroom 110, within segment 155 ₁ to a certain location 175 ₂ withinsegment 155 ₂ may be determined and compared to a first certain lengthof time t_(1,2) (FIG. 1) that is determined based on the distancebetween certain location 175 ₁ and certain location 175 ₂ and the speedof carrier 125. Similarly, the length of time it takes for carrier 125to travel from the certain location 175 ₂ to a certain location 175 ₃within segment 155 ₃ may be determined and compared to a second certainlength of time t_(2,3) (FIG. 1) that is determined based on the distancebetween certain location 175 ₂ and certain location 175 ₃ and the speedof carrier 125. The length of time it takes for carrier 125 to travelfrom the certain location 175 ₃ to a certain location 175 _(N), e.g.,that coincides with end location 120 on sales floor 115, within segment155 _(N) may also be determined and compared to an (N−1)th certainlength of time t_(3,N) (FIG. 1) that is determined based on the distancebetween certain location 175 ₃ and certain location 175 _(N) and thespeed of carrier 125. For one embodiment, controller 160 is configuredto perform the timing only during certain times of day, e.g.,corresponding to the stocking times for location 120.

For an alternative embodiment, when carrier 125 arrives at location 175₂ within segment 155 ₂ within the length of time t_(1,2), controller 160may be further configured to determine whether carrier 125 travels fromlocation 175 ₂ to location 175 ₂′ within segment 155 ₂ within a certainintermediate length of time t_(2,2′) (FIG. 1) that is determined basedon the distance between location 175 ₂ and location 175 ₂′ and the speedof carrier 125. For example, for another embodiment, the length of timeit takes for carrier 125 to travel from location 175 ₂ to location 175₂′ may be determined and compared to the length of time t_(2,2′).Controller 160 may then determine whether carrier 125 travels fromlocation 175 ₂′ to location 175 ₃ within a certain length of timet_(2′,3) (FIG. 1) that is determined based on the distance betweenlocation 175 ₂′ and location 175 ₃ and the speed of carrier 125. Forexample, for one embodiment, the length of time it takes for carrier 125to travel from location 175 ₂′ to location 175 ₃ may be determined andcompared to the length of time length of time t_(2′,3). Controller 160may then determine whether carrier 125 travels from location 175 ₃ tolocation 175 _(N) within the length of time t_(3,N), as described above.Note that timing between successive locations within a segment 155, asdescribed and shown for segment 155 ₂, may occur for other segments 155along path 155 for embodiments where those segments, including segments155 ₁, 155 ₃, and 155 _(N), include one or more additional timinglocations.

For one embodiment, controller 160, and thus the monitoring system, maybe configured to operate in a normal mode of operation, where controller160 causes cameras 150 to capture video or to capture and display videoor to record and store video, and to transition to thesecurity-zone-monitoring mode of operation in response to a certainevent, such as the occurrence of a certain time of day corresponding toone of the stocking times for location 120. For another embodiment, themonitoring system may be configured to transition from the normaloperating mode to a timing mode of operation in response to the certainevent and to transition to the security-zone-monitoring mode in responseto a certain other event, such as when carrier 125 arrives at a certainlocation of path 135 within a certain time. For example, the monitoringsystem may transition from the timing mode to thesecurity-zone-monitoring mode in response to carrier 125 arriving atlocation 175 ₂′ from location 175 ₁ without any timing violations, whenlocation 175 ₂′ is included in segment 155 ₂, or carrier 125 arriving atlocation 175 ₃ from location 175 ₁ without any timing violations whenlocation 175 ₂′ is not included in segment 155 ₂.

For one embodiment, when operating in the timing mode, the monitoringsystem records and stores video and times the progress of carrier 125along path 135. For example, controller 160 determines whether carrier125 travels between successive path locations 175 within a certain time.For one embodiment, controller 160 may be configured to indicate anoccurrence of a timing violation whenever a timing violation occurs whenoperating in the timing mode. For example, when operating in the timingmode, controller 160 may indicate, e.g., on video display 162, that atiming violation occurred in the form of an informational message, e.g.,informing a user that a timing violation occurred. The message mayinclude the location of the camera that last captured an image ofcarrier 125 just prior to or at the time of the timing violation and thetime at which the timing violation occurred. For one embodiment, whenoperating in the timing mode, controller 160 may treat a timingviolation as a false alarm by indicating that a false alarm occurred.For another embodiment, controller 160 exits the timing mode and returnsto the normal mode of operation in response to a timing violation.

For one embodiment, when operating in the security-zone-monitoring mode,the monitoring system records and stores video and times the progress ofcarrier 125 along path 135. For example, controller 160 determineswhether carrier 125 travels between successive path locations 175 withina certain time. For one embodiment, controller 160 may be configured toindicate an occurrence of a timing violation whenever a timing violationoccurs when operating in the security-zone-monitoring mode. For anotherembodiment, controller 160 may be configured to indicate a timingviolation in the form of an alarm, such as a path-violation alarm, onlywhile operating in the security-zone-monitoring mode. For example, apath-violation alarm may be indicated in conjunction with the timingviolation only while operating in the security-zone-monitoring mode. Foranother embodiment, controller 160 exits the security-zone-monitoringmode and returns to the normal mode of operation in response to a timingviolation and thus a path-violation alarm.

For another embodiment, controller 160 may stop the timing of carrier125 in response to any timing violation, regardless of whethercontroller 160 is operating in the timing mode orsecurity-zone-monitoring mode. For example, controller 160 may exit thesecurity-zone-monitoring mode or the timing mode in response to a timingviolation and enter the normal operating mode. For one embodiment,cameras 150 may record and store video all the time, but it is onlyduring the security-zone-monitoring mode and the timing mode thatcontroller 160 times the progress of carrier 125 along path 135 ordetermines when carrier 125 has left location 122, as described above.For another embodiment, it is only while operating in thesecurity-zone-monitoring mode that path-violation alarms are issued fora timing violation.

For another embodiment, controller 160 may be configured to indicate apath-violation alarm, e.g., in the form of a message displayed on videodisplay 162 or displayed and/or stored as part of an alarm log. That is,when the length of time it takes for carrier 125 to travel betweencertain locations within successive segments 155 exceeds the certainlength of time based on the distance between those certain locations orthe time it takes for carrier 125 to travel between certain locationswithin a single segment 155, a timing violation occurs. For example,when the length of time it takes for carrier 125 to travel from location175 ₁ to location 175 ₂ exceeds the length of time t_(1,2), a timingviolation occurs, and controller 160 will indicate a path-violationalarm when operating in the security-zone-monitoring mode. When thelength of time it takes for carrier 125 to travel from location 175 ₂ tolocation 175 ₂′, when location 175 ₂′ is included in segment 155 ₂,exceeds the length of time t_(2,2′), a timing violation occurs, andcontroller 160 will indicate a path-violation alarm when operating inthe security-zone-monitoring mode. When the length of time it takes forcarrier 125 to travel from location 175 ₂ to location 175 ₃, whenlocation 175 ₂′ is not included in segment 155 ₂, exceeds the length oftime t_(2,3) or when the length of time it takes for carrier 125 totravel from location 175 ₂′ to location 175 ₃, when location 175 ₂′ isincluded in segment 155 ₂, exceeds the length of time t_(2′,3), a timingviolation occurs, and controller 160 will indicate a path-violationalarm when operating in the security-zone-monitoring mode. When thelength of time it takes for carrier 125 to travel from location 175 ₃ tolocation 175 _(N) exceeds the length of time t_(3,N), a timing violationoccurs, and controller 160 will indicate a path-violation alarm whenoperating in the security-zone-monitoring mode.

For one embodiment, indicating a path-violation alarm in response to atiming violation may include controller 160 displaying an indicator,e.g., on display 162, indicating that a path-violation alarm hasoccurred. The indicator may also indicate the date and time thepath-violation alarm occurred and the last camera to capture the imageof carrier 125 at a time just prior to or at the time of thepath-violation alarm. For one embodiment, an indicator is displayed foreach path-violation alarm that has occurred, e.g., as part of an alarmlog.

For another embodiment, the date and time that each video frame for eachcamera was captured is added to the image data for that frame.Therefore, for one embodiment, a user may input the day and time of apath-violation alarm into a search engine of controller 160 and performa global search of the image data files to locate the video for eachcamera that was taken, starting at the time of the path-violation alarm.For another embodiment, the time indicated by the indicator may be justprior to the time of the path-violation alarm to enable the retrieval ofvideo that was taken just prior to the time of the path-violation alarm.For example, the global search may be based on a time just prior to thetime of the path-violation alarm. For another embodiment, the user maydisplay the video for each camera and fast-forward through the videountil the frame corresponding to the date and time of the path-violationalarm appears.

For one embodiment, controller 160 may be configured to indicate alocation within the database where video taken by each camera, startingat the time of the path-violation alarm or just prior to the time of thepath-violation alarm, is stored. For example, in one embodiment,controller 160 may be configured to tag (e.g., bookmark) a location inthe image data file, e.g. a specific frame, in response to apath-violation alarm, for each camera, corresponding to the time of thepath-violation alarm. For example, controller 160 may be configured toadd an identifier to the image data corresponding to the frame capturedby each camera at the time of the path-violation alarm or a time justprior to the time of the path-violation alarm. In addition, thepath-violation alarm indicated by controller 160 in response to thetiming violation may include the identifier, so that the user can inputthe identifier into a global search of the image data files to locatethe image data, for each camera, corresponding to the timing violation.In another embodiment, controller 160 may be configured to indicate,e.g., on display 162, each path-violation alarm and the location instorage device 170 of the image data recorded by each camera 150,starting at the time of the path-violation alarm or a time just prior tothe time of the path-violation alarm.

For another embodiment, controller 160 may be configured to create, inresponse to a path-violation alarm, image data files specifically forstoring video from each camera 150 that was activated, starting at thetime of the path-violation alarm or a time just prior to the time of thepath-violation alarm and ending at a certain time after thepath-violation alarm, e.g., about a length of time it takes for carrier125 to traverse the distance from the stockroom to location 120.Controller 160 may be further configured to indicate the names of thesefiles in response to the path-violation alarm, e.g., in an alarm log.

For one embodiment, controller 160 may be configured to place a marker(e.g., known as a “video tripwire”) in the image field captured by eachof cameras 150 ₁ to 150 _(N) that coincides with a respective one ofeach of locations 175 ₁ to 175 _(N) (FIG. 1). For example, FIG. 2illustrates image fields 210 ₁ to 210 _(N) respectively captured bycameras 150 ₁ to 150 _(N). That is, image fields 210 ₁ to 210 _(N)respectively contain the images of segments 155 ₁ to 155 _(N) asrespectively captured by cameras 150 ₁ to 150 _(N). Note that markers(e.g., “video tripwires”) 220 ₁ to 220 _(N) are respectively located inimage fields 210 ₁ to 210 _(N) and respectively coincide with locations175 ₁ to 175 _(N) along path 135 for embodiments where segment 155 ₂does not include location 175 ₂′. Note further that, markers 220 ₁ and220 _(N) respectively coincide with starting location 122 and endinglocation 120 (FIG. 1). In an alternative embodiment, markers 220 ₁ to220 _(N) respectively coincide with locations 175 ₁ to 175 _(N) andmarker 220 ₂′ is located in image field 210 ₂ and coincides withlocation 175 ₂′ for embodiments where segment 155 ₂ includes location175 ₂′.

For embodiments where location 175 ₂′ is not included in segment 155 ₂,controller 160 determines the length of time it takes for carrier 125 totravel between successive locations 175 by measuring the time thatelapses from when a portion of the image of carrier 125, e.g., a frontend 172 (FIG. 2), crossed a marker 220 within the image field 210 thatcontains one of the successive locations 175 until the portion of thecarrier crossed a marker 220 within the image field 210 that containsthe next one of the successive locations 175. For example, at an instantof time when front end 172 crosses marker 220 ₁ in image field 210 ₁, asshown in FIG. 2, in a certain direction, e.g., in the direction of arrow230 ₁, controller 160 starts timing the travel of carrier 125 betweenlocations 175 ₁ and 175 ₂. At the instant of time front end 172 crossesmarker 220 ₂ in image field 210 ₂ in the direction of arrow 230 ₂,controller 160 compares the time that elapsed from when front end 172crossed marker 220 ₁ until front end 172 crossed marker 220 ₂, i.e., thetravel time between locations 175 ₁ and 175 ₂, to the length of timet_(1,2) and starts timing the travel of carrier 125 between locations175 ₂ and 175 ₃ when the travel time between locations 175 ₁ and 175 ₂is less than or equal to the length of time t_(1,2). At the instant oftime front end 172 crosses marker 220 ₃ in image field 210 ₃ in thedirection of arrow 230 ₃, controller 160 compares the time that elapsedfrom when front end 172 crossed marker 220 ₂ until front end 172 crossedmarker 220 ₃, i.e., the travel time between locations 175 ₂ and 175 ₃,to the length of time t_(2,3) and starts timing the travel of carrier125 between locations 175 ₃ and 175 _(N) when the travel time betweenlocations 175 ₂ and 175 ₃ is less than or equal to the length of timet_(2,3). At the instant of time front end 172 crosses marker 220 _(N) inimage field 210 _(N) in the direction of arrow 230 _(N), controller 160compares the time that elapsed from when front end 172 crossed marker220 ₃ until front end 172 crossed marker 220 _(N), i.e., the travel timebetween locations 175 ₃ and 175 _(N), to the length of time t_(3,N) andstops timing when the travel time between locations 175 ₃ and 175 _(N)is less than or equal to the length of time t_(3,N). Note thatcontroller 160 indicates a path-violation alarm, when operating in thesecurity-zone-monitoring mode, when a travel time exceeds the certaintime to which that travel time is compared, but keeps timing untilcarrier 125 reaches location 120 when each travel time is less than orequal to the respective one of the certain times to which that traveltime is compared. For another embodiment, the monitoring system mayreturn to the normal operating mode when carrier 160 arrives at location120 without a timing violation.

For embodiments where timing occurs between locations within a singlesegment 155, such as between locations 175 ₂ and 175 ₂′ within segment155 ₂, the timing of carrier 125 may proceed as follows. At an instantof time when front end 172 crosses marker 220 ₁ in the direction ofarrow 230 ₁, controller 160 starts timing the travel of carrier 125between locations 175 ₁ and 175 ₂. At the instant of time front end 172crosses marker 220 ₂ in the direction of arrow 230 ₂, controller 160compares the time that elapsed from when front end 172 crossed marker220 ₁ until front end 172 crossed marker 220 ₂, i.e., the travel timebetween locations 175 ₁ and 175 ₂, to the length of time t_(1,2) andstarts timing the travel of carrier 125 between locations 175 ₂ and 175₂′ when the travel time between locations 175 ₁ and 175 ₂ is less thanor equal to the length of time t_(1,2). At the instant of time front end172 crosses marker 220 ₂′ in image field 210 ₂ in the direction of arrow230 ₂′, controller 160 compares the time that elapsed from when frontend 172 crossed marker 220 ₂ until front end 172 crossed marker 220 ₂′,i.e., the travel time between locations 175 ₂ and 175 ₂′, to the lengthof time t_(2,2′) and starts timing the travel of carrier 125 betweenlocations 175 ₂′ and 175 ₃ when the travel time between locations 175 ₂and 175 ₂′ is less than or equal to the length of time t_(2,2′). At theinstant of time front end 172 crosses marker 220 ₃ in the direction ofarrow 230 ₃, controller 160 compares the time that elapsed from whenfront end 172 crossed marker 220 ₂′ until front end 172 crossed marker220 ₃, i.e., the travel time between locations 175 ₂′ and 175 ₃, to thelength of time t_(2,3) and starts timing the travel of carrier 125between locations 175 ₃ and 175 _(N) when the travel time betweenlocations 175 ₂′ and 175 ₃ is less than or equal to the length of timet_(2′,3). At the instant of time front end 172 crosses marker 220 _(N)in the direction of arrow 230 _(N), controller 160 compares the timethat elapsed from when front end 172 crossed marker 220 ₃ until frontend 172 crossed marker 220 _(N), i.e., the travel time between locations175 ₃ and 175 _(N), to the length of time t_(3,N) and stops timing whenthe elapsed travel time between locations 175 ₃ and 175 _(N) is lessthan or equal to the length of time t_(3,N). Note that controller 160indicates a path-violation alarm when operating in thesecurity-zone-monitoring mode when a travel time exceeds the certaintime to which that travel time is compared, but keeps timing untilcarrier 125 reaches location 120 when each travel time is less than orequal to the respective one of the certain times to which that traveltime is compared.

For one embodiment, controller 160 may be configured to determinewhether carrier 125 travels between successive locations 175 bydetermining whether an image of carrier 125 appears crossing a markerwithin an image field corresponding to a location 175 within a certaintime after crossing a marker in an image field corresponding to apreceding location 175. For example, for timing between locations 175 ₁and 175 ₂, when the image of carrier 125 does not appear crossing marker230 ₂ within image field 210 ₂ within the length of time t_(1,2) aftercrossing marker 230 ₁ within image field 210 ₁, a timing violationoccurs between locations 175 ₁ and 175 ₂. When the image of carrier 125does appear crossing marker 230 ₂ within the length of time t_(1,2)after crossing marker 230 ₁, there is no timing violation betweenlocations 175 ₁ and 175 ₂, and controller 160 proceeds with timingcarrier 125 between the next locations 175, e.g., between locations 175₂ and 175 ₂′, when location 175 ₂′ is included in segment 155 ₂, orbetween locations 175 ₂ and 175 ₃, when location 175 ₂′ is not includedin segment 155 ₂. For example, when the image of carrier 125 does notappear crossing marker 230 ₂ within image field 210 ₂ within the lengthof time t_(2,2′) after crossing marker 230 ₂ or the image of carrier 125does not appear crossing marker 230 ₃ within image field 210 ₃ withinthe length of time t_(2,3) after crossing marker 230 ₂, a timingviolation occurs. When the image of carrier 125 does appear crossingmarker 230 ₂′ within the length of time t_(2,2′) after crossing marker230 ₂ or crossing marker 230 ₃ within the length of time t_(2,3) aftercrossing marker 230 ₂, there is no timing violation, and controller 160proceeds with timing cart between the next locations 175 in a similarmanner until a timing violation occurs or until carrier 125 reacheslocation 175 _(N), which coincides with end location 120.

For one embodiment, controller 160 is configured to initiate the timingbetween locations 175 ₁ and 175 ₂ in response to the image of carrier125 crossing the marker 220 ₁ in image field 210 ₁ captured by thecamera 150 ₁. For another embodiment, controller 160 is furtherconfigured to cause marker 220 ₂ to be superimposed on image field 210 ₂captured by the camera 150 ₂ in response to the image of carrier 125crossing the marker 220 ₁.

Controller 160 may be further configured to initiate the timing betweenlocations 175 ₂ and 175 ₂′ in response to the image of carrier 125crossing the marker 220 ₂ in image field 210 ₂, e.g., when the traveltime of carrier 125 between locations 175 ₁ and 175 ₂ is less than orequal to the length of time t_(1,2). For another embodiment, controller160 may be further configured to cause marker 220 ₂ to be superimposedon image field 210 ₂ in response to the image of carrier 125 crossingthe marker 220 ₂ when the travel time of carrier 125 between locations175 ₁ and 175 ₂ is less than or equal to the length of time t_(1,2). Foryet another embodiment, controller 160 may cause both marker 220 ₂ andmarker 220 ₂′ to be superimposed on image field 210 ₂ in response to theimage of carrier 125 crossing the marker 220 ₁.

Alternatively, when location 175 ₂′ is not included in segment 155 ₂,controller 160 may be further configured to initiate the timing betweenlocations 175 ₂ and 175 ₃ in response to the image of carrier 125crossing the marker 220 ₂ in image field 210 ₂ when the travel time ofcarrier 125 between locations 175 ₁ and 175 ₂ is less than or equal tothe length of time t_(1,2). For another embodiment, controller 160 maybe further configured to cause marker 220 ₃ to be superimposed on imagefield 210 ₂ in response to the image of carrier 125 crossing the marker220 ₂ when the travel time of carrier 125 between locations 175 ₁ and175 ₂ is less than or equal to the length of time t_(1,2).

For one embodiment, controller 160 may transition from the timing modeof operation to the security-zone-monitoring mode of operation inresponse to the travel time of carrier 125 between locations 175 ₂ and175 ₂′ being less than or equal to the length of time t_(2,2′), whenlocation 175 ₂′ is included in segment 155 ₂, or in response to thetravel time of carrier 125 between locations 175 ₂ and 175 ₃ being lessthan or equal to the length of time t_(2,3), when location 175 ₂′ is notincluded in segment 155 ₂. For one embodiment, controller 160, and thusthe monitoring system, may be configured to operate thesecurity-zone-monitoring mode of operation from the time when controller160 detects the image of carrier 125 crossing the marker 220 ₁ in imagefield 210 ₁, or controller 160 may be configured to transition from thetiming mode of operation to the security-zone-monitoring mode ofoperation in response to the travel time of carrier 125 betweenlocations 175 ₂ and 175 ₂′ being less than or equal to the length oftime t_(2,2′), when location 175 ₂′ is included in segment 155 ₂, or inresponse to the travel time of carrier 125 between locations 175 ₂ and175 ₃ being less than or equal to the length of time t_(2,3), whenlocation 175 ₂′ is not included in segment 155 ₂. For example,controller 160 may transition from the timing mode of operation to thesecurity-zone-monitoring mode of operation when image carrier 125reaches location 175 ₂′ from location 175 ₁, when location 175 ₂′ isincluded in segment 155 ₂, without any timing violations, as determinedfrom the image of carrier 125 crossing marker 220 ₂′ in the direction ofarrow 230 ₂′ in image field 210 ₂ (FIG. 2). Alternatively, controller160 may transition from the timing mode of operation to thesecurity-zone-monitoring mode of operation when image carrier 125reaches location 175 ₃ from location 175 ₁, when location 175 ₂′ is notincluded in segment 155 ₂, without any timing violations, as determinedfrom the image of carrier 125 crossing marker 220 ₃ in the direction ofarrow 230 ₃ in image field 210 ₃ (FIG. 2).

For the embodiment where location 175 ₂′ is included in segment 155 ₂,controller 160 may be further configured to initiate the timing betweenlocations 175 ₂′ and 175 ₃ in response to the image of carrier 125crossing the marker 220 ₂′, e.g., when the travel time of carrier 125between locations 175 ₂ and 175 ₂′ is less than or equal to the lengthof time t_(2,2′). For another embodiment, controller 160 may be furtherconfigured to cause marker 220 ₃ to be superimposed on image field 210 ₃in response to the image of carrier 125 crossing the marker 220 ₂′ whenthe travel time of carrier 125 between locations 175 ₂ and 175 ₂′ isless than or equal to the length of time t_(2,2′). Controller 160 may befurther configured to initiate the timing between locations 175 ₃ and175 _(N) in response to the image of carrier 125 crossing the marker 220₃, e.g., when the travel time of carrier 125 between locations 175 ₂′and 175 ₃ is less than or equal to the length of time t_(2′,3). Foranother embodiment, controller 160 may be further configured to causemarker 220 _(N) to be superimposed on image field 210 _(N) in responseto the image of carrier 125 crossing the marker 220 ₃ when the traveltime of carrier 125 between locations 175 ₂′ and 175 ₃ is less than orequal to the length of time t_(2′,3).

For the embodiment where location 175 ₂′ is not included in segment 155₂, controller 160 may be configured to initiate the timing betweenlocations 175 ₃ and 175 _(N) in response to the image of carrier 125crossing the marker 220 ₃, e.g., when the travel time of carrier 125between locations 175 ₂ and 175 ₃ is less than or equal to the length oftime t_(2,3). For another embodiment, controller 160 may be furtherconfigured to cause marker 220 _(N) to be superimposed on image field210 _(N) in response to the image of carrier 125 crossing the marker 220₃ when the travel time of carrier 125 between locations 175 ₂ and 175 ₃is less than or equal to the length of time t_(2,3).

In an alternative embodiment, the timing commences in response todetermining that the image of carrier 125 captured by camera 150 ₁ hasleft the image field (e.g., image field 210 ₁) captured by camera 150 ₁,using the methods described above. For example, when an image of anobject, corresponding to carrier 125, of a certain size has been absentfrom image field 210 ₁ for a certain time, e.g., about five seconds,camera 150 ₂ is activated, and the timing of carrier 125 from startinglocation 122 captured by camera 150 ₁ to location 175 ₂ within segment155 ₂ captured by camera 150 ₂ occurs by determining the elapsed timefrom when the image of carrier 125 was last present in image field 210 ₁until when the image of carrier 125 crosses marker 220 ₂ in image field210 ₂. For another embodiment, marker 220 ₂ is displayed in image field210 ₂ in response to determining that the image of carrier 125 has leftimage field 210 ₁. It should be understood that the certain times fortravel of carrier 125 between respective locations may vary fromlocation to location and from facility to facility.

FIG. 3 is a flowchart of a method 300 of monitoring a path, such as path135, of a facility, such as retail store 100, using a plurality ofcameras, such as cameras 150 ₁ to 150 _(N), directed at the path,according to another embodiment. At block 310, it is determined that anobject, e.g., corresponding to carrier 125, is absent from the imagefield captured by the camera directed at the starting location, e.g.,location 122, of path 135. For one embodiment, this involves determiningthat the object has a certain size and has been absent from that imagefield for a certain time, as described above. For a further embodiment,upon determining that the object is absent from image field 210 ₁ (FIG.2) captured by camera 150 ₁ directed at location 122 (FIG. 1) of path135, controller 160 determines that carrier 125 is absent from the imagefield 210 ₁, and thus that carrier 125 has left location 122.

At block 320, the video captured by each of the cameras, e.g., each ofcameras 150 ₁ to 150 _(N), is displayed and/or stored in response todetermining that the object is absent from the image field captured bythe camera directed at the starting location of path 135. For example,the video captured by each of cameras 150 ₁ to 150 _(N) may be stored instorage device 170 and/or displayed on video monitors 166 ₁ to 166 _(N)(FIG. 1) or on video display 162. For one embodiment, the video capturedby each of the plurality of cameras is displayed and/or stored at onlycertain times of day, e.g., when retail store 100 is closed, forstocking location 120 with items contained in carrier 125.

FIG. 4 is a flowchart of a method 400 of monitoring a path, such as path135, of a facility, such as retail store 100, according to anotherembodiment. At block 410, it is determined whether carrier 125 travelsfrom a first location of the path 135 to a second location of path 135within a certain time. For example, it is determined whether carrier 125travels from any one of locations 175 to the next location 175 (FIG. 1)within a certain time. For one embodiment, determining whether carrier125 travels from a first location 175 to a second location 175 (FIG. 1)within the certain time involves determining whether an image of carrier125 crosses a marker 220 on an image field 210 (FIG. 2) captured by acamera 150 directed at the second location 175 within the certain timeafter determining that the image of carrier 125 moves past a marker 220on an image field 210 captured by a camera directed at the firstlocation 175. For another embodiment, before determining whether thecarrier travels from the first location 175 to the second location 175within the certain time, the marker 220 is superimposed on the imagefield 210 captured by the camera 150 directed at the second location inresponse to determining that the image of carrier 125 moves past themarker 220 on the image field 210 captured by the camera 150 directed atthe first location of the path. For another embodiment, the camera 150directed at the second location of the path and the camera directed atthe first location of the path is a single camera, such as camera 150 ₂,as shown in FIG. 1.

At block 420 a timing violation is indicated when carrier 125 fails totravel from the first location to the second location within the certaintime. For one embodiment, an alarm is indicated in conjunction withindicating the timing violation, e.g., when controller 160, and thus themonitoring system, is operating in the security-zone-monitoring mode.

For another embodiment, when carrier 125 travels from the first locationof the path to the second location of the path within a first time, itis determined whether carrier 125 travels from the second location ofthe path to a third location of the path within a second time. Foranother embodiment, the third location is the ending location 120 ofpath 135, and the timing of carrier 125 is stopped when carrier 125travels from the second location to the third location within the secondtime, e.g., controller 160 returns to the normal operating mode from thesecurity-zone-monitoring mode in response to carrier 125 reachinglocation 120 without incurring any time violations.

CONCLUSION

Although specific embodiments have been illustrated and described hereinit is manifestly intended that the scope of the claimed subject matterbe limited only by the following claims and equivalents thereof.

What is claimed is:
 1. A method of monitoring a path of a facility usinga plurality of cameras directed at the path, the method comprising:determining that an object is absent from an image field captured by acamera of the plurality of cameras that is directed at a startinglocation of the path at least in part by using a controller having atleast one electronic component to analyze data from the camera of theplurality of cameras that is directed at a starting location of thepath; and displaying and/or storing video captured by each of theplurality of cameras in response to said controller determining that theobject is absent from the image field captured by the camera directed atthe starting location of the path.
 2. The method of claim 1, whereindetermining that the object is absent from the image field captured bythe camera directed at the starting location of the path comprisesdetermining that the object has a certain size and has been absent fromthat image field for a certain time.
 3. The method of claim 1, furthercomprising determining that a carrier has left the starting location ofthe path upon determining that the object is absent from the image fieldcaptured by the camera directed at the starting location of the path.